In manufacturing a semiconductor device, various processing apparatuses (semiconductor apparatuses) are used to perform processings such as, for example, oxidation, diffusion, chemical vapor deposition (CVD), or annealing on a processing target object, for example, a substrate such as, for example, a semiconductor wafer (hereinafter, simply referred to as a “wafer”). As one of the processing apparatuses, there is known a batch-processing type substrate heat treatment apparatus which is capable of performing a heat treatment on a plurality of wafers at once.
In the batch-processing type substrate heat treatment apparatus, a plurality of wafers is conveyed from the outside of the apparatus by a conveyance container (a carrier) (also referred to as a “FOUP”) which accommodates the plurality of wafers. The conveyance container is supplied into the substrate heat treatment apparatus through, for example, a load port of the apparatus which is a carry-in/out port of the apparatus. The wafers are taken out of the supplied conveyance container and transferred to a boat (a holder) which is capable of holding the plurality of wafers at predetermined intervals in the height direction. The wafers in each boat are inserted into a heat treatment furnace and subjected to various processings.
In such a substrate heat treatment apparatus, it is requested that a processing time be reduced or a throughput be improved. In order to reduce the processing time, the substrate heat treatment apparatus is requested to store as many conveyance containers as possible, and replace the wafers held by a boat quickly whenever a processing is completed within the heat treatment furnace. Accordingly, for example, Japanese Laid-Open Patent Publication No. 2006-120658 discloses an exemplary configuration of a vertical heat treatment apparatus, which is a kind of substrate heat treatment apparatus configured to dispose many conveyance containers therein.
The apparatus disclosed in Japanese Laid-Open Patent Publication No. 2006-120658 is an apparatus that handles wafers with a diameter of 300 mm. It has recently been required to handle wafers with a diameter of 450 mm. When the wafer diameter increases in this manner, the wafer thickness also increases. Thus, the size of a conveyance container holding the wafers also increases.
Although, the size of wafers to be supplied to a substrate heat treatment apparatus increases as described above, a substrate heat treatment apparatus is requested to have a throughput equal to or higher than that of a conventional substrate heat treatment apparatus designed to handle wafers with a diameter of 300 mm, and a footprint (an occupied area) substantially equal to that of the conventional substrate heat treatment apparatus. Accordingly, the substrate heat treatment apparatus that handles wafers with a diameter of 450 mm is requested to have a footprint substantially equal to that of the conventional substrate heat treatment apparatus that handles wafers with a diameter of 300 mm, and be configured to store substantially the same number of wafers therein as that of the conventional substrate heat treatment apparatus.